[Tracking] Important manually review work for DarkMode for Preview 7

[KlausLoeffelmann]

• Make ToolStripDarkModeRenderer sealed (Fix DarkMode (a) StatusStrip background renderer A11Y Regression. #13360 (comment))
• Make GetDarkModeColorMode more efficient Fix DarkMode (a) StatusStrip background renderer A11Y Regression. #13360 (comment)
• Follow-up on GraphicsInternal issue in the ToolStripRenderer (Fix DarkMode (a) StatusStrip background renderer A11Y Regression. #13360 (comment)) also see (Fix DarkMode (a) StatusStrip background renderer A11Y Regression. #13360 (comment))
• Followup on Windows version in DarkMode renderer Fix DarkMode (a) StatusStrip background renderer A11Y Regression. #13360 (comment)
• Making the DarkModeButtonColors sealed (DarkMode (b) DarkModeButtonRenderer #13408 (comment))
• Make the rules for XML comments more precicise for refactoring purposes. DarkMode (b) DarkModeButtonRenderer #13408 (comment)
• The Button renderer docs are very confusing, and I want to sit with Andy to see what we can do for it. (DarkMode (b) DarkModeButtonRenderer #13408 (comment) - also @adegeo FYI.)
• Extend on comment for purpose of code change. (DarkMode (b) DarkModeButtonRenderer #13408 (comment))
• Weird comment, needs to be addressed. DarkMode (b) DarkModeButtonRenderer #13408 (comment)
• Redundant comment. DarkMode (b) DarkModeButtonRenderer #13408 (comment)
• Make sure to restore any deliberately Graphics mode back to normal (several spots:)
  • DarkMode (b) DarkModeButtonRenderer #13408 (comment)
  • DarkMode (b) DarkModeButtonRenderer #13408 (comment)

[Zheng-Li01]

Verified related DarkMode issues about this PR, all issues have been fixed except the issue 12027